A lookout
tower set atop the roof of a residence *kyokan
居館, usually a lord's residence for looking out over the surrounding area
to observe enemy forces and to order troop movements. Earliest extant examples
are the 1576 Tenshu 天守 of Maruokajou 丸岡城, Fukui prefecture, and the
1601 Inuyamajou 犬山城, Aichi prefecture.